Method and apparatus for controlling a digital phase lock loop within a cordless telephone

摘要

A digital phase lock loop controller (DPLL) (10) incorporates an adjustment generator (34) for continually adjusting the sensitivity of the DPLL (10) to reduce injected noise. The DPLL also comprises an error detector (16), a frequency adjuster (22), a first oscillation generator (28), and a divider (32) that function in a manner common to many DPLLs (10). However, the adjustment generator (34) continually adjusts the operation of the frequency adjuster (22) based upon the relative phase difference between a reference oscillation (12) and a feedback oscillation (14) in order to vary the sensitivity of the DPLL (10). When the reference oscillation (12) and the feedback oscillation (14) are relatively in phase, the sensitivity of the DPLL (10) is low. Oppositely, when the reference oscillation (12) and the feedback oscillation (14) move out of phase, the sensitivity of the DPLL (10) increases. <IMAGE>